import java.io.IOException;
import java.net.*;
import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:UDP客户端
 * User: wangxin
 * Date: 2024-08-12
 * Time: 15:15
 */
public class UDPEchoClient {
    private DatagramSocket socket = null;
    private String serverIP;
    private int serverPort;
    public UDPEchoClient(String serverIP,int serverPort) throws SocketException {
        socket = new DatagramSocket();
        this.serverIP = serverIP;
        this.serverPort = serverPort;
    }
    public void start() throws IOException {
        System.out.println("启动客户端！");
        Scanner scanner = new Scanner(System.in);
        while(true){
            //1.从客户端读取用户的输入。
            System.out.print
                    ("->");
            String request = scanner.next();
            //2.构造出一个UDP请求，发送给服务器
            DatagramPacket requestPacket = new DatagramPacket(request.getBytes(),request.getBytes().length,
                    InetAddress.getByName(this.serverIP),this.serverPort);
            socket.send(requestPacket);
            //3.从服务器读到响应
            DatagramPacket responsePacket = new DatagramPacket(new byte[4096],4096);
            socket.receive(responsePacket);
            String response = new String(responsePacket.getData(),0,responsePacket.getLength());
            //4.把响应打到控制台上。
            System.out.println(response);
        }


    }

    public static void main(String[] args) throws IOException {
        UDPEchoClient client = new UDPEchoClient("127.0.0.1",9090);
        client.start();
    }
}
